Implantable electrical stimulation systems have proven therapeutic in a variety of diseases and disorders. For example, spinal cord stimulation systems have been used as a therapeutic modality for the treatment of chronic pain syndromes. Peripheral nerve stimulation has been used to treat chronic pain syndrome and incontinence, with a number of other applications under investigation. Functional electrical stimulation systems have been applied to restore some functionality to paralyzed extremities in spinal cord injury patients.
Stimulators have been developed to provide therapy for a variety of treatments. A stimulator can include a control module (with a pulse generator), one or more leads, and an array of stimulator electrodes on each lead. The stimulator electrodes are in contact with or near the nerves, muscles, or other tissue to be stimulated. The pulse generator in the control module generates electrical pulses that are delivered by the electrodes to body tissue.
The pulse generators typically planted within the patient's body have an outer casing and a header made of bio-compatible material. The electronic components such as RF transceivers inside the casing are interfaced with the lead through a hermetically sealed assembly known as a feedthrough assembly. Strong electromagnetic environments, such as MRI (magnetic resonance imaging) scans, can produce induced RF currents that may be detrimental.